Compare Versions - i18next

26.4.0

perf: cache toResolveHierarchy results per (code, fallbackCode) pair. The hierarchy resolver runs on every t() call and calls Intl.getCanonicalLocales multiple times, which showed up prominently when profiling render-heavy UIs (e.g. virtualized data grids); with the cache the per-call cost drops from ~886 ns to ~41 ns. The cache is invalidated automatically when options.fallbackLng changes (reassignment or in-place array mutation); if you mutate other resolution-relevant options at runtime (load, lowerCaseLng, cleanCode, nonExplicitSupportedLngs), call i18next.services.languageUtils.clearCache() afterwards. Function-valued fallbackLng and per-call array/object fallbackLng options are never cached, so dynamic fallbacks keep working as before. Thanks @equaterina (#2444).
chore: update all devDependencies (Babel stays on 7.x until @rollup/plugin-babel supports 8, eslint on 9.x for neostandard). Removed the unused coveralls package (CI uses the Coveralls GitHub Action) and replaced sinon with nise + vitest.spyOn in the v1 compatibility tests, which resolves all open npm audit findings (0 vulnerabilities) and should close the dependabot alerts on the lockfile.

26.3.6

fix: allow TypeScript 7 in the optional typescript peer dependency range (^5 || ^6 || ^7). With typescript@7.0.2 in a project, npm install failed with an ERESOLVE peer conflict. The published types are TS7-compatible as-is: every test/typescript suite produces identical results under 6.0 and 7.0.2. Reported in react-i18next#1927, thanks @andikapradanaarif.

26.3.5

fix: $t() nesting options blocks that span multiple lines are now parsed. nest() decided where the nested key ends by testing match[1] with /{.*}/, whose dot does not cross line breaks — so a $t(key, { ... }) options object containing a newline was treated as having no options, mis-split as formatters, and the nested lookup ran without its options (placeholders stayed unresolved). The nesting regexp itself already matches newlines inside $t(...); adding the s (dotAll) flag makes multiline options behave like the single-line form. Thanks @spokodev (#2440).
fix: getUsedParamsDetails (the returnDetails: true path) no longer mutates the passed replace object. It wrote count straight onto options.replace so the returned usedParams would include it — a caller reusing one replace object across t() calls then carried a stale count into later interpolations (e.g. a previous call's count: 5 rendered instead of the current call's value). The details are now built from a copy; usedParams still includes count. Thanks @spokodev (#2441).
fix: with the default skipOnVariables: true + escapeValue: true, a {{placeholder}} carried inside an interpolated value now stays literal even when the value contains escapable characters. The skip logic advanced the regex lastIndex by the raw value length, but the escaped text written into the string is longer, so lastIndex landed inside the inserted value and a trailing {{placeholder}} in it got interpolated — leaking another in-scope variable that should have stayed literal (values without escapable characters were already skipped correctly). The advance now uses the escaped length that is actually written, and the regex-safe $-doubling is applied only at the String.replace call so it can't distort the length arithmetic. Thanks @spokodev (#2442).

26.3.4

fix(security): deepExtend (used by addResourceBundle(..., deep, overwrite)) no longer recurses into inherited properties. It checked key existence with the in operator, which walks the prototype chain, so a source key matching an inherited built-in (e.g. hasOwnProperty, toString) caused recursion into the shared Object.prototype function and, with overwrite: true, could overwrite e.g. Object.prototype.hasOwnProperty.call with a non-callable value — corrupting a shared built-in process-wide (DoS). Existence is now checked with Object.prototype.hasOwnProperty.call, so such keys are copied as plain own data instead. This complements the existing __proto__/constructor guard and is also strictly more correct for an own-property merge. Only affects applications that pass attacker-controlled data with deep: true and overwrite: true; no standard backend/integration does this. Distinct from CVE-2026-48713 / CVE-2026-48714 (different packages, setPath mechanism). See advisory GHSA-6jcc-5g8w-32mx, CVSS 5.9 (CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:H). Thanks to zx (Jace) @manus-use for the responsible disclosure.

26.3.3

fix(types): selector t($ => $.arr, { returnObjects: true, context }) on a JSON array of heterogeneous objects now preserves each element's full shape (e.g. { transKey1: string; transKey2: string }[]) instead of collapsing to a union of partial element types. Two type-level causes: (1) FilterKeys evaluated the whole array element type at once, so keyof (A | B) only saw the keys common to every element — it now distributes over the object union and filters each element independently; (2) when TypeScript merges mismatched array element types it injects phantom optional undefined keys (e.g. transKey1_withContext?: undefined on elements that don't define it), which the context-detection helpers mistook for real context variants — they now skip keys typed as undefined. Also adds a dedicated context + returnObjects: true selector overload using const Fn + ReturnType<Fn>, so Target is no longer collapsed to unknown via ApplyTarget. Resolves Problem 1 of #2398 (Problem 2 was already fixed on master). Thanks @sauravgupta-dotcom (#2438). Fixes #2398.

26.3.2

fix: chained formatters with a parenthesised option that contains the format separator (e.g. join(separator: ', ')) now work at any position in the chain, not just first. Previously the comma-in-parens reassembly only repaired formats[0], so {{v, uppercase, join(separator: ', ')}} split the join(...) option on the inner comma and never rejoined it, producing corrupt output. Replaced the first-position-only repair with a position-independent pass that re-joins fragments until each open paren closes. Thanks @spokodev (#2437).

26.3.1

fix(types): t() with a keyPrefix no longer pollutes its return type with sibling keys' values. A regression in 26.3.0 — the [Res] extends [never] guards added to KeysBuilderWithReturnObjects / KeysBuilderWithoutReturnObjects turned the builders into deferred conditional types, so KeyPrefix<Ns> stopped resolving to a literal union and keyPrefix inference widened to the whole namespace. Symptom: useTranslation(ns, { keyPrefix: 'a.b' }) then t('title') would resolve to '<a.b>.title' | '<other.path>.title' | ... instead of just the scoped value. Affected every react-i18next user using keyPrefix. Restored to the eager 26.2.0 form. The same-namespace conflict handling from #2434 still works via _DropConflictKeys at the merge layer (in options.d.ts). Thanks @aaronrosenthal (#2436).

26.3.0

feat(types): introduce ResourceNamespaceMap — a separate mergeable augmentation surface for namespace resource types, designed for monorepos where multiple packages each want to contribute their own namespaces. Previously, every package had to coordinate on a single CustomTypeOptions.resources declaration (or fall back to typing dependency namespaces as any) because resources is a single property of an interface and TypeScript reports TS2717 when two declarations of the same property disagree. The new interface merges naturally across declare module 'i18next' blocks, so each package can ship its own i18next.d.ts independently. Per-property merge handles same-namespace contributions from multiple packages, and same-key/different-literal conflicts are silently dropped to avoid poisoning t() overload resolution. Fully backwards-compatible — existing CustomTypeOptions.resources augmentations continue to work, and both surfaces can coexist. Scalar options (defaultNS, returnNull, enableSelector, etc.) still belong on CustomTypeOptions. Thanks @sh3xu (#2434). Fixes #2409.

26.2.0

feat(types): new parseInterpolation TypeOption (default true). When set to false in CustomTypeOptions, the type-level extractor stops parsing translation strings for {{variable}} patterns. Required by i18next-icu users — the default extractor mistakes ICU MessageFormat nested-brace plurals like {count, plural, one {{count} row} other {{count} rows}} for an interpolation block and demands a phantom variable name. The flag is type-only; runtime interpolation is governed by InterpolationOptions and is unaffected. Fixes i18next-icu#85.
fix(types): expose enableSelector on InitOptions so i18next.init({ enableSelector: 'strict' }) typechecks without a module augmentation. The runtime already reads opts?.enableSelector from init options; this lands the matching type declaration next to the other selector-resolution knobs. Accepts false | true | 'optimize' | 'strict'. Thanks @Faithfinder (#2431)

26.1.0

feat: enableSelector: 'strict' (TypeOptions + runtime option). Opt-in mode that drops the flattened-primary form from NsResource at the type level — every namespace (primary included) is exposed only under its own key on $, uniformly across single- and multi-ns hooks. At runtime, a leading selector path segment matching the scope's namespace list is always rewritten as a namespace prefix, including the primary. Eliminates the silent-miss surface area where t($ => $.primary.foo) typechecks but doesn't resolve under the default mode (see #2429). Backward-compatible: default enableSelector: false | true | 'optimize' behavior is unchanged. Note: strict mode is incompatible with the #2405 pattern (keys whose names match sibling namespaces) — those users should stay on default mode.

26.0.10

feat: getFixedT accepts a fourth optional fixedOpts argument carrying scopeNs — the full namespace list the bound t was created for. The selector API uses scopeNs to detect when a path's first segment is a namespace prefix, without changing resolution scope. Resolution still uses the bound ns (a single primary string in the typical react-i18next setup), so plain t('key') lookups stay isolated to the primary namespace exactly as before — only t($ => $.secondaryNs.foo) selectors now route correctly under useTranslation([nsA, nsB]). Fixes the runtime side of #2429 for the react-i18next default-nsMode case. The 4th argument is opt-in: existing 3-arg getFixedT(lng, ns, keyPrefix) callers see no behavior change.

26.0.9

fix(types): unformatted interpolation values are now typed as string | number (was string). i18next stringifies values at runtime, so requiring callers to wrap numbers in String(...) for plain {{var}} placeholders was unnecessary friction — and could mask the real problem when a non-string value was passed alongside multiple interpolation slots (the t() overload resolution would fall through to the 3-arg form and report a confusing "not assignable to string" error against the options object). Typed format specifiers like {{x, number}}, {{x, currency}}, {{x, datetime}}, etc. keep their precise types; this only relaxes the no-format default. The count variable remains number-only

26.0.8

fix(types): restore the pre-v25.10.4 ExistsFunction shape so plain arrow functions can again be assigned to ExistsFunction-typed variables (TypeScript cannot infer type predicates through multi-overload assignment). Direct i18next.exists(key) calls still narrow key to SelectorKey — the predicate is now declared inline on i18n.exists. Custom wrappers that want the narrowing can type themselves as typeof i18next.exists 2425

26.0.7

fix: when a plural lookup misses, the missingKey debug log now shows the actual plural-resolved key (e.g. foo.bar_many for Polish count: 14) instead of the base key — making it obvious which plural category was expected and missing 2423
chore: drop @babel/runtime runtime dependency. The build no longer generates any @babel/runtime imports, so the package is unused by consumers. Rollup now uses babelHelpers: 'bundled' so any helpers that are ever needed in the future will be inlined rather than imported externally 2424
chore: stop emitting dist/esm/i18next.bundled.js. It was byte-identical to dist/esm/i18next.js because no helpers were being imported 2424

26.0.6

Security release — all issues found via an internal audit.

security: warn when a translation string combines escapeValue: false with interpolated variables inside a $t(key, { ... "{{var}}" ... }) nesting-options block. In that narrow combination, attacker-controlled string values containing " can break out of the JSON options literal and inject additional nesting options (e.g. redirect lng/ns). The default escapeValue: true configuration is unaffected because HTML-escaping neutralises the quote before JSON.parse. See the security note in the Nesting docs for the full pattern and mitigations
security: apply regexEscape to unescapePrefix / unescapeSuffix on par with the other interpolation delimiters. Prevents ReDoS (catastrophic-backtracking) when a misconfigured delimiter contains regex metacharacters, and fixes silent breakage of the {{- var}} syntax when the delimiter contains characters like (, [, .
security: strip CR/LF/NUL and other C0/C1 control characters from string log arguments to prevent log forging via user-controlled translation keys, language codes, namespaces, or interpolation variable names (CWE-117)
chore: ignore .env* and *.pem/*.key files in .gitignore

26.0.5

fix: cloneInstance().changeLanguage() no longer fails to update language state when the target language is not yet loaded — a race between init()'s deferred load() and the user's changeLanguage() could overwrite isLanguageChangingTo, causing setLngProps to be skipped 2422

26.0.4

fix(types): inline formatting options like {{price, currency(EUR)}} are now correctly resolved to their base format type (e.g. number for currency) instead of falling back to string 2378

26.0.3

fix(types): addResourceBundle now accepts an optional 6th options parameter ({ silent?: boolean; skipCopy?: boolean }) matching the runtime API 2419

26.0.2

fix(types): t("key", {} as TOptions) no longer produces a type error — the context constraint now bypasses strict checking when context is unknown (e.g. from TOptions) 2418

26.0.1

fix: Formatter no longer crashes when alwaysFormat is true and no format specifier is present (format is undefined)
fix: Formatter now returns undefined/null values as-is instead of producing NaN when the value is missing

26.0.0

This is a major breaking release:

Breaking Changes

Remove deprecated initImmediate option — the backward-compatibility mapping from initImmediate to initAsync (introduced in v24) has been removed. Use initAsync instead.
Remove legacy interpolation.format function — the old monolithic format function (interpolation: { format: (value, format, lng) => ... }) is no longer supported. The built-in Formatter (or a custom Formatter module via .use()) is now always used. Migrate to the new formatting approach using i18next.services.formatter.add() or .addCached() for custom formatters.
Remove console support notice — the console support notice introduced in v25.8.0 has been removed, along with the showSupportNotice option and all related internal suppression logic (globalThis.__i18next_supportNoticeShown, I18NEXT_NO_SUPPORT_NOTICE env var). See our blog post for the full story.
Remove simplifyPluralSuffix option — this option was unused by the core PluralResolver (which relies entirely on Intl.PluralRules). It only had an effect in the old v1/v2/v3 compatibility layer. The v4 test compatibility layer now defaults to true internally.
Remove deprecated @babel/polyfill from devDependencies.

Improvements

Code modernization across all source files:
- Replace indexOf() > -1 / indexOf() < 0 with .includes() (~40+ occurrences)
- Replace indexOf() === 0 with .startsWith() where appropriate
- Replace var with const, '' + object with String(object), .substring() with .slice()
- Replace .apply(observer, [event, ...args]) with direct call observer(event, ...args)
- Remove unnecessary .call(this, ...) in BackendConnector retry logic
- Fix array-callback-return in LanguageUtils getBestMatchFromCodes
- Clean up all stale eslint-disable comments from source files
EventEmitter: add once() method for one-time event subscriptions
Memory leak fix: move module-level checkedLoadedFor cache to Translator instance, preventing cross-instance state leakage
TypeScript: fix BackendModule generic parameter naming inconsistency between CJS and ESM type definitions
TypeScript: add once() method to i18n and ResourceStore type interfaces
ESLint 9: migrate from ESLint 8 (airbnb-base) to ESLint 9 flat config with neostandard
Vitest 4: upgrade from vitest 3 to vitest 4, migrate workspace files to test.projects config

25.10.10

feat: suppress support notice automatically in production environments (NODE_ENV=production)

25.10.9

feat(types): export SelectorParam<Ns, KPrefix> helper type — a stable, readable alternative to Parameters<TFunction<Ns>>[0] for typing selector function props 2414

25.10.8

fix(types): reorder TFunctionSelector overloads so Parameters<TFunction> resolves to the general selector signature instead of the branded SelectorKey type 2412

25.10.7

feat(types): support typescript 6 to address https://github.com/i18next/react-i18next/issues/1910

25.10.5

feat(types): selector functions as keyPrefix in getFixedT now provide full type-safe key narrowing — the returned t function is scoped to the prefix subtree 2367

25.10.4

feat(types): i18nKey of <Trans i18nKey={sk} /> to accept a SelectorKey 2364

25.10.3

check also for I18NEXT_NO_SUPPORT_NOTICE env variable

25.10.2

feat(types): keyFromSelector is now type-safe — the selector callback is constrained against your resource definitions, catching invalid keys at compile time. Supports optional ns and keyPrefix options for non-default namespace/prefix contexts 2364

25.10.1

fix(types): FilterKeys now correctly excludes base keys that have context variants when the provided context doesn't match any of them (e.g. key some with variant some_me is no longer accessible with context="one")

25.10.0

feat(types): keyFromSelector now returns a branded SelectorKey type that t() accepts directly, enabling pre-computed and reusable translation keys 2364
feat: support selector syntax for keyPrefix in getFixedT and per-call options 2367
feat(types): interpolation values are now automatically typed based on built-in format specifiers — {{val, number}} requires number, {{val, datetime}} requires Date, {{name}} requires string, etc. Custom formatters can be typed via interpolationFormatTypeMap in CustomTypeOptions 2378
fix(types): FilterKeys in selector mode now preserves non-context, non-plural leaf keys when context is provided, fixing incorrect type narrowing when combining returnObjects: true with context 2398

25.9.0

feat(types): selector API now enforces { count: number } when a key resolves to plural forms 2373
fix(types): string unions with invalid members are now correctly detected as type errors when used as context option 2172

25.8.20

- fix: getFixedT() selector now resolves namespaces against the effective ns rather than the global init options #2406

25.8.19

fix: selector API namespace resolution regression for single-string ns and primary namespace in array #2405. Reverts the broad namespace-prefix rewrite from v25.8.15 and replaces it with a targeted fix that only rewrites paths starting with a secondary namespace in a multi-namespace array, matching the type-level contract of GetSource

25.8.18

improve selector api to accept array of selector functions, analogous to array of keys 2404

25.8.17

update deps

25.8.16

fix(types): on() method now correctly returns this instead of void, matching the runtime behavior and enabling proper method chaining in TypeScript

25.8.15

fix: Selector API unable to resolve namespaces #2402

25.8.14

fix: getCleanedCode now replaces all underscores

25.8.13

improve support notice shown logic

25.8.12

improve support notice shown logic

25.8.11

revert fix: compatibility with moduleResolution bundler (issue 2380) 2381

25.8.10

fix(interpolator): guard null matchedDoubleQuotes in nesting option parsing 2395

25.8.9

fix(interpolator): escape nestingOptionsSeparator in nesting option parsing 223943

25.8.8

types(i18n): add missing toJSON() declaration 2393

25.8.7

avoid crash due to ReferenceError without Intl API 2391

25.8.6

ts: address incomplete type definition for getFixedT() return value 2318

25.8.5

fix: compatibility with moduleResolution bundler (issue 2380) 2381

25.8.4

fix: crashes when backend in backends array has no name property 2386

25.8.3

ts: document option to suppress the support message 2385

25.8.2

option to suppress the support message 2385

25.8.1

fix(types): Selector API - fix Namespace inference for selector ns option 2384

25.8.0

fix: TFunctionReturn fallback 2360

25.7.4

fix: Interpolation breaks when cloning an instance 2376

25.7.3

type definitions for new transDefaultProps option in react-i18next react-i18next: #1895

25.7.2

fix: Invalid overwrite of default value for overloadTranslationOptionHandler 2374.

25.7.1

TS: remove wrong signature 2372.

25.7.0

Enhance cloneInstance to create a new interpolator if interpolation options are passed in. This will address 2371.

25.6.3

chore: dependency updates 2368

25.6.2

types: export InterpolationMap

25.6.1

fix: createInstance does not exist on an instance #2366

25.6.0

feat: exists() method now respects returnObjects option - returns false when accessing an object key with returnObjects: false, enabling detection of object vs string keys 2359

Note: This is a potential behavior change. If you were previously calling exists() with returnObjects: false on object keys, those calls will now return false instead of true. This enables developers to detect whether a key points to an object or string value.

25.5.3

export esm type declaration for keyFromSelector 2356

25.5.2

fix last change => for cjs there is just 1 default export, no named exports, fixes 2348

25.5.1

export keyFromSelector from index.cjs 2347

25.5.0

export keyFromSelector function for testing purposes 2346

25.4.2

fix: enableSelector: true doesn't work with custom keySeparator 2341

25.4.1

fix: KeyPrefix not working with new selector api 2340

25.4.0

add new selector API to improve TypeScript IDE performance 2322
- To enable it, set enableSelector: true in your configuration options
- With enableSelector: "optimize", i18next can now handle translation dictionaries of any size, without affecting IDE performance or build times
- To assist with the migration, we've published the following packages:
  - @i18next-selector/codemod
  - @i18next-selector/vite-plugin

25.3.6

improve fix: Ordinals and non-ordinals don't work together 2337

25.3.5

fix: Ordinals and non-ordinals don't work together 2337

25.3.4

remove unnecessary debug logs

25.3.3

fix: Brackets breaking nesting interpolation 2336

25.3.2

fix dir() for non-Intl language codes 2330

25.3.1

warn if legacy interpolation.format function is still used

25.3.0

feat: support formatting function with plural and interpolation 2325
fix dir() for Latn language codes 2324

25.2.1

streamline fallbackLng option of t call with the init options 2312

25.2.0

introduce cacheInBuiltFormats option to address 2227

25.1.3

Ensure nsSeparator is respected when appendNamespaceToMissingKey is true 2311, fixes 2310

25.1.2

do not mutate t options, fixes 2307

25.1.1

fix options type for parseMissingKeyHandler

25.1.0

feat: parseMissingKeyHandler now takes options as parameter like in missingKeyHandler 2304

25.0.2

fix cloneInstance with forkResourceStore: true addresses 2303

25.0.1

optimize changeLanguage to correctly use getBestMatchFromCodes (string or array) 2299 and improve resolvedLanguage set for non canonical codes

25.0.0

This is a potentially breaking release:

fix multiple changeLanguage call that may have result in wrong order in previous versions 1605 2298
adapt changeLanguage to always (string or array) use getBestMatchFromCodes 2299
getBestMatchFromCodes now tries to fallback to language code with same script 2299

24.2.3

Upgrade @babel/runtime package to version v7.26.10 2293

24.2.2

fix: Interpolation fails with arrays (TypeError) and doesn't work with objects in defaultValue 1829

24.2.1

Standardize null/undefined checks across codebase 2275
fix(typescript): make TFunction augmentable again 2279, fixes 2278

24.2.0

feat(typescript): Add strictKeyChecks option to enforce checking key existence when defaultValue is used 2274, fixes 2043

24.1.2

optimize fix: Bug Report: Unsafe Behavior in i18n.t Function Leading to Potential Code Execution 2273

24.1.1

fix: Bug Report: Unsafe Behavior in i18n.t Function Leading to Potential Code Execution 2273

24.1.0

try to address 2270 by cloning the store data 2271

24.0.5

remove extra log for 2268

24.0.4

simplify fix: incorrect locale detected 2268

24.0.3

fix: incorrect locale detected 2268
fix: Intl.getCanonicalLocales throws with custom regions 2267

24.0.2

if no Intl api, log error and use dummy rule

24.0.1

early return and log error, if no Intl api

24.0.0

This is a major breaking release:

remove support for older environments
remove old i18next JSON formats
- To convert your existing v3 translations to the v4 format, have a look at i18next-v4-format-converter or this web tool.
remove support for compatibility to v1 API
Intl API is mandatory now and will not fallback anymore
possible compatibility layer for older formats: test/compatibility/v4/v4Compatibility.js
rename initImmediate to initAsync
fallback to dev language if plural rule not found
remove TypeScript v4 support. TypeScript v5 is now an optional peer dependency
addresses
- 2244
- 2184
- 2213
- 2206
- 2208
- 2148
- 2254

➡️ check out the migration guide

23.16.8

fix(plural): Create cache entry for PluralRules created as part of the fallback flow 2256

23.16.7

if plural rule is not found, try to search with language only code 2252

23.16.6

fix: Small typo in the type definitions 2250

23.16.5

fix extractFromKey for use cases like this

23.16.4

revert formatter change 2247 because of caching not working anymore

23.16.3

fix utils imports for Deno

23.16.2

perf(size): Adds a isString utility 2248

23.16.1

perf: Optimize size of Formatter 2247

23.16.0

use Intl.getCanonicalLocales function if available to format language code, like suggested in 2244

23.15.2

fix(types): make context related keys detection stricter 2243 fixes 2242

23.15.1

types(TFunction): make return not inferrable and use defaultValue as return when provided 2234

23.15.0

support unescaped variables in TypeScript 2233

23.14.0

If backend errors with retry flag, set internal state to 0, so reloadingResources should work 147

23.13.0

Cache output of getRule to optimize performance 2226

23.12.7

revert last optimization to address 2227

23.12.6

remove console.log statement 2227

23.12.5

try to optimize last fix for 2227

23.12.4

try to address 2227 without the removal of cached formatter for in-built formatters

23.12.3

fix: Using a comma in a formatter parameter 2225

23.12.2

fix: Nested translation resolution between languages uses the fallback language for nested translations 2216 by preserving issue fix "lng is undefined when formatter used in $t( )" 1938

23.12.1

Use explicit imports for utils 2212

23.12.0

feat: Add posibility to override keyPrefix for certain translation. 2211

23.11.5

perf: use Array.isArray() 2193
perf: trim keys once 2194

23.11.4

perf(interpolator): use object deconstruction 2181

23.11.3

fix: Unsupported language is automatically added to preload option 2178

23.11.2

allow defaultValue in nested translation 2174

23.11.1

types: remove const from ParseKeys Context type parameter and disable skipLibCheck 2169

23.11.0

Fix typing performance regression 2166

23.10.1

optimize getBestMatchFromCodes for https://github.com/i18next/i18next-browser-languageDetector/issues/281

23.10.0

Add 'isInitializing' property so we're able to detect init() was already called 2141

23.9.0

types: support nested keys in InterpolationMap 2140 fixes 2014

23.8.3

prevent resource mutation when using addResourceBundle 2081

23.8.2

optimize addResources to address 2130

23.8.1

types: support stricter typechecking for returnEmptyString and returnNull 2129

23.8.0

improve performance by reducing array slices and RegExp recreation 2128

23.7.20

optimize: consistent _zero special handling also for defaultValue_zero 2124
intl plural rule for dev is now en (consistent with v3 compatibility)

23.7.19

fix: consistent _zero special handling also for defaultValue_zero 2124

23.7.18

types: support readonly defaultNS 2123

23.7.17

types: fix support for defaultNS as array (fixes 2118) 2121
types: fix typo in CustomInstanceExtensions 2122

23.7.16

fix: Use Typescript 5 types with Typescript 5+ 2108
- Hint: If you're using TypeScript 4 and you navigate to the type definitions in your code editor, it might be you will see the TypeScript 5 types, but the TS compiler should use the correct types.

23.7.15

types: simplifies types for array access and fixes 2103

23.7.14

types: fix types for array access

23.7.13

types: optimise ParseTReturn 2095

23.7.12

types: fix for older ts version (context validation only for TS 5)

23.7.11

types: fix for older ts versions 2090

23.7.10

types: initializedStoreOnce and initializedLanguageOnce 2089

23.7.9

types: fix FormatFunction should allow any value inside options parameter

23.7.8

prevent cosmetic SyntaxError because of non catched error variable

23.7.7

optimize TypeScript V4 export

23.7.6

types: CustomInstanceExtenstions

23.7.5

fix types export for TypeScript v4 in combination with react-i18next

23.7.4

fix for TypeScript v4 in combination with react-i18next

23.7.3

fix: consider importing '*.js'

23.7.2

types: optimize mts

23.7.1

fix some mjs typings

23.7.0

fix: separate cjs and mjs typings 2010
fix: consider importing './typescript/t.js' 2048

23.6.0

add interpolation data to response if returnDetails is true 2053

23.5.1

types: use unknown to better infer types on nested t functions also for older typescript version 2032

23.5.0

types: use unknown to better infer types on nested t functions 2018

23.4.9

fix: preload languages also on cimode, if configured also as fallbackLng

23.4.8

fix: preload languages also on cimode, if configured

23.4.7

preload languages also on cimode, if configured

23.4.6

pass correct language for custom i18nFormat

23.4.5

types: named export for FlatNamespace

23.4.4

types: add customisation of contextSeparator also on v4 t types 2019

23.4.3

types: add customisation of contextSeparator 2017

23.4.2

types: export some types for next-i18next

23.4.1

types: fix typescript imports

23.4.0

types: Support const modifier for options and key 2007
types: Support context 2006

23.3.0

types: Fix performance issue that affects flat object with multiple (thousands) keys 2004

23.2.11

types: Fix $TFunctionBrand 1997

23.2.10

types: emit function can have additional arguments 1993

23.2.9

types: Add brand to TFunction type so different namespaces' TFunctions are not treated as compatible 1994

23.2.8

types for hasLoadedNamespace

23.2.7

fix utils import (for Deno)

23.2.6

Re-allow unknown keys, when a defaultValue is provided 1867

23.2.5

Clean language code before passing to formatters 1985

23.2.3

types: Optimize logic for fallback ns 19198481

23.2.2

types: try to fix fallbackNS type handling also for older TS version 1981

23.2.1

types: fix fallbackNS type handling 1979

23.2.0

types: add fallbackNS type handling 1975

23.1.0

cloneInstance: introduce forkResourceStore 1974
types: default argument values for ParseKeys type

23.0.2

refactor: static createInstance for wider browser support 1973

23.0.1

types: export ParseKeys

23.0.0

This is a major breaking release:

redesigned TypeScript types 1911 (use TypeScript v5)
removed setDebug function in the logger: 1954
changed returnNull default to false 1885
drop support for old browsers and Node.js < v12 1948
ordinal plural keys are now prefixed with _ordinal to help translators (non-breaking, bacause of fallback) 1945

➡️ check out the migration guide

22.5.1

ResourceStore addResource: offer possibility to pass keySeparator via options 1968

22.5.0

extend hasLoadedNamespace function options to pass optional lng to optimize server side usage of react-i18next

22.4.15

fix: function t() passed options alteration 1947

22.4.14

fix: pass lng to format function used in nesting 1938

22.4.13

fix: deepFind as fallback for interpolation 1930

22.4.12

fix: getBestMatchFromCodes when dev is a supported lng 1927

22.4.11

types: fix postProcessor key argument type, fixes 1919

22.4.10

format options are optional, fixes 1913

22.4.9

fix: getFixedT with keyPrefix and fallback keys usage 1604

22.4.8

fix: nested interpolation with data model "replace"

22.4.7

fix: interpolation with data model "replace"

22.4.6

types: missing dir function export for typescript

22.4.5

types: allow als general options as second argument for t function

22.4.4

types: fix some strang t function overloads fixes 1882

22.4.3

types: t function overloads fix (open issue is still calling t with optional options argument)

22.4.2

types: t function overloads for call with ns option in combination with objects

22.4.1

types: more t function overloads for call with options argument but without ns value

22.4.0

types: more overloads for t function

22.3.0

offer possibility to define a language detector's detect function as promise

22.2.0

types: extend the init method with a generic parameter for backend options 1878, 105, 34

22.1.5

types: ability to pass ns as option instead of prefix i.e. i18next.t('bar', { ns: 'alternate' });

22.1.4

dir function executible also without initialization

22.1.3

named export for dir function

22.1.2

revert: guess if languageDetector is async if no info provided

22.1.1

guess if languageDetector is async if no info provided

22.1.0

extend backend connector to accept also backends with promise / async-await signature

22.0.8

fix options for continuous nesting 1876

22.0.7

Expose some types 1871

22.0.6

fix CallbackError type

22.0.5

Change DefaultTFuncReturn to return null if returnNull typeOption is true 1865

22.0.4

Add type for Formatter.addCached 1862

22.0.3

Make getFixedT type-safe 1860
types: Omit object from t function 1858

22.0.2

[TypeScript] Add default value for TDefaultResult 1853

22.0.1

Fix normalize type options 1850

22.0.0

Make the translation function fully type-safe 1775

BREAKING: Since this is a major rewrite for TypeScript usage we decided to create a major version. For JavaScript users v22.0.0 is equivalent to 21.10.0

21.10.0

Add formatter cache 1843

21.9.2

optimize single quotes replacement for $t() nesting 1836

21.9.1

defaultNS can now also be set to false

21.9.0

Add Customizable Retry Logic 1810
types: extend compatibilityJSON with v4

21.8.16

types: fix getDataByLanguage type 1810

21.8.15

fix: make sure retry logic ends for failed backend reads

21.8.14

allow overriding keyPrefix option t function returned from getFixedT (does not work for normal t function)

21.8.13

types: new optional unescape option for react-i18next

21.8.12

fix: respect pluralSeparator for special _zero handling

21.8.11

fix: types should always come first in exports 1796

21.8.10

types: fix loaded event result

21.8.9

fix: deepFind for null values 1790

21.8.8

fix: loadNamespaces() doesn't keep resolving order when the second request completes before the first one 1785

21.8.6

fix: regression introduced in v21.6.11, respect appendNamespaceToMissingKey for parseMissingKeyHandler 1507

21.8.5

fix: interpolation with $ in values resets nextIndex to wrong position with skipOnVariables 1782

21.8.4

types: keyPrefix in react options

21.8.3

prevent chrome warnings because of window.navigator.userAgent usage 1778

21.8.2

types: add saveMissingPlurals option 1774

21.8.1

fix regression introduced with 1768

21.8.0

add maxParallelReads option, default 10 1771
reduce CPU usage loading large numbers of items 1768

21.7.1

types: missing returnDetails option in init options 1765

21.7.0

introduce returnDetails option 1764

21.6.16

fix: defaultVariables were not accessible inside plugin parse function 1751

21.6.15

fix hasLoadedNamespace when providing inmemory resources and a backend but partialBundledLanguages is not set

21.6.14

fix formatter for false inline options

21.6.13

make sure resolvedLanguage is set if lazy loading resources

21.6.12

fix ordinal-suffixes for saveMissingWithPlurals 1734

21.6.11

make sure key and additionally optional defaultValue are passed to parseMissingKeyHandler function 1445

21.6.10

fix: types for hasLoadedNamespace 1724

21.6.9

fix: respect skipOnVariables option passed in t function also for $t() usage

21.6.8

fix: respect skipOnVariables option passed in t function

21.6.7

fix: consistently lowercase new formatter names internally

21.6.6

fix: deepFind fallback when accessing missing flat dotted key 1719

21.6.5

fix: passed format parameter value truncation in options argument for custom formatter 1715

21.6.4

fix: skipOnVariables (and all other interpolation options should respect defaults) 1711

21.6.3

types: wait option does not exist anymore for react-i18next

21.6.2

remove console.log statement

21.6.1

fix when completely lazy loading namespaces 1709

21.6.0

add _zero suffix lookup if count === 0 1705

21.5.6

fix: correct defaults for plural forms (if supplied) 1703

21.5.5

fix: prevent TypeError when using returnObjects: true with non string values 1702

21.5.4

include version info in generated package.json of esm dist

21.5.3

do not use options.interpolation reference

21.5.2

missing named exports for TypeScript usage 1692

21.5.1

add package.json to exports subpath

21.5.0

named exports for esm usage 1681

21.4.2

trim multiple formatters, fixes 1689

21.4.1

rtl fix for -arab language codes

21.4.0

bind all i18next functions to this, this way you can for example just use t() instead of i18n.t() 1682

21.3.3

apply default interpolation formatter when interpolation options don't specify one 1680

21.3.2

formatter typescript declarations 1679

21.3.1

get rid of internal isDummy check to prevent react-native issue 1675

21.3.0

adds support for formats provided by Intl API (number, currency, datetime, relativedate, list)

21.2.6

optimize do skip natural language detection also if user provided nsSeparator option is passed via direct options

21.2.5

do skip natural language detection also if user provided nsSeparator option is passed 1665

21.2.4

optimize Intl api check

21.2.3

fix Intl.PluralRules fallback

21.2.2

log error if Intl.PluralRules API is not available

21.2.1

do skip natural language detection, if user provided keySeparator option is passed 1670

21.2.0

provide bundled esm distributable 1667

21.1.1

optimize natural language detection 1661

21.1.0

A new RTL support added for ckb language code

21.0.2

fix defaultNS regression if translation namespace is defined in ns option, fixes #1658

21.0.1

fix typescript typo for skipOnVariables

21.0.0

This is a major breaking release:

introduce new v4 json format (intl plural forms with ordinal support), simplifyPluralSuffix not used anymore
skipOnVariables by default now is true
automatically detect natural language keys (no need to set nsSeparator or keySeparator to false)
remove deprecated whitelist features
introduce new i18next.resolvedLanguage property

➡️ check out the migration guide